The designation of the Florida Keys National Marine Sanctuary by Congress in 1990 was prompted by a series of cumulative events of environmental degradation, the threat of oil drilling, and vessel groundings. Today, more than 2.5 million people visit the Keys each year, and of those, 70 percent visit the waters of the Sanctuary to fish, dive, and boat. The economy of the Keys is dependent upon the reefs and the activities they support. Photo courtesy of Harold Hudson, Florida Keys NMS.